Deciphering Sounds Over Background Noise May Diagnose Reading Problems


In an effort to determine whether children are at risk for later learning difficulties, new research has found it may be possible to predict which preschoolers will struggle with learning to read.

Studies are showing that the predictor has to do with how the brain deciphers speech in the midst of a noisy background. Lauran Neergaard of Associated Press writes that researchers from Northwestern University have analyzed brain waves of children as young as three and drawn remarkable conclusions.

If a young person is able to recognize consonants while background noise is present, researchers have determined that they are more likely to have less difficulty with reading development, the team reported this week in the journal PLOS Biology. If this method is perfected, it is possible it will become a “biological looking glass.” Senior author of the study Nina Kraus, Director of Northwestern’s Auditory Neuroscience Laboratory, said:

 “If you know you have a 3-year-old at risk, you can as soon as possible begin to enrich their life in sound so that you don’t lose those crucial early developmental years.”

Preschoolers who can match sounds to letters at an early age go on to become readers more easily. This is because auditory processing is part of pre-reading development, and if the brain is slow to distinguish a “D” from a “B” sound, for example, recognizing words and constructing sentences could also be affected.

Noise stresses the system because the brain has to block out competing sounds in order to focus and in fractions of milliseconds. Vowels are less vulnerable to noise than consonants, according to Kraus. The brain’s response to sound is measured using an EEG, which includes attaching electrodes to the child’s scalp and recording the patterns of electric activity as nerve cells fire off.

Then, the team created a model to predict children’s abilities on early literacy tests. After that, they did a set of experiments with 112 kids 3- to 14-years-old. The test, which took 30 minutes, predicted 3-year-olds performance on a language-development skill and how the same young people scored after a year on a series of standard pre-reading evaluations. The scientists said time will show how well those children will read in the future.

The most common reasons that reading is a struggle for millions of children are because of learning disabilities or a lack of exposure to spoken language. Scientists are able to help children who have these two problems, but early identification of the kids who are shown to need help becomes the real problem, writes Nathan Collins reporting for Pacific Standard Magazine. This is why the new brain/noise/consonant test is such a breakthrough.

“Learning to read is a chief developmental milestone with lifelong consequences,” write Travis White-Schwoch, Nina Kraus, and colleagues.”[A]lthough there are effective interventions for struggling readers, an ongoing challenge has been to identify candidates for intervention at a young-enough age.”

The team put 37 four-year-olds in individual booths to watch a movie. In one ear, they piped sounds of six people babbling and an audio of a single person repeating the syllable “da.” The movie’s audio could be heard with the other ear. Simultaneously, the electrical activity in the kids’ brains was monitored. A brain that could identify the “da”  in spite of the babbling was a brain that was ready to learn to read.

This testing is complicated and expensive, and further research is needed, but Kraus is hopeful that the time will come when monitoring a child’s brain for processing sound may be a routine newborn hearing screening.